#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int main()
{
	int a, b, c = 0;
	while (scanf("%d %d %d", &a, &b, &c) != EOF)
	{
		if ((a + b - c) * (a - b + c) * (-a + b + c)>0)
		{
			if (a == b&&a == c)
			{
				printf("Equilateral triangle!\n");
			}
			else if (a == b || b == c || c == a)
			{
				printf("Isosceles triangle!\n");
			}
			else
				printf("Ordinary triangle!\n");
		}
		else
			printf("Not a triangle!\n");
	}
}